Correlation of cellular traction forces and dissociation kinetics of adhesive protein zyxin by means of multidimensional microscopy

LORENA SIGAUT; MICAELA BIANCHI; CATALINA VON BILDERLING; LÍA I PIETRASANTA

San Luis

Congreso; XLVIII Reunión Anual Sociedad Argentina de Biofísica; 2019

Cells exert traction forces on the extracellular matrix to which they are adhered through the formation of focal adhesion. Spatial-temporal regulation of traction forces is crucial in cell adhesion, migration, cellular division and remodeling of the extracellular matrix. By cultivating cells on polyacrylamide hydrogels of di erent sti ness we were able to investigate the e ects of substrate sti ness on the generation of cellular traction forces by Traction Force Microscopy (TFM), and characterize the molecular dynamic of focal adhesion protein zyxin by Fluorescence Correlation Spectroscopy (FCS) and Fluorescence Recovery After Photobleaching (FRAP). As the rigidity of the substrate increases, we observed an increment of both, cellular traction generation and zyxin residence time at the focal adhesion, while its di usion would not be altered. Moreover, we found a linear correlation between the traction forces exerted by cells and the residence time of zyxin at the substrate elasticity studied. We found that this correlation persists at the focal adhesion level, even if there is no variation in substrate sti ness, by performing combined TFM and FRAP experiments, revealing that focal adhesions that exert greater traction, present longer residence time for zyxin, i.e. zyxin protein has less probability to dissociate from the focal adhesion.